by Sandy Guldman
According to the book Larkspur Past and Present, the main part of Piper Park, established in 1971, had been an uncontrolled dump for several years. A former City Councilman is quoted as saying, “People brought…anything they wanted to get rid of and left it on the site.”
Recordkeeping was poor, and available maps did not show that the dump had extended into the far west side of Piper Park where the dog park was located.
Zooming forward 45 years, permits issued for construction of the new Bon Air Bridge required mitigation measures to both reduce impacts of the project and to compensate for lost habitat. Specifically, to compensate for the loss of tidal wetlands caused by the wider new bridge, the City of Larkspur agreed to develop a new dog park at Piper Park and create new tidal wetlands at the site of the existing dog park. A few borings were made on the site of the dog park and nothing unusual was encountered.
Unfortunately, excavation soon revealed that the mapping was incomplete and that the borings did not accurately represent what appeared: old tires and concrete rubble. At that point, the Marin County Health Department shut down construction, just in case the site was contaminated with hazardous material. This guaranteed that the project could not be completed by the end of October 2023.
The City consulted with the regulatory agencies and agreed that the site would be covered for winter to keep sediment from being washed into the marsh. A cap of Bay Mud that had already been delivered to the site, intended for use in the restoration, was placed on the excavated area. The extra Bay Mud is stored in a pile on the site and covered with a tarp. Although the bare dirt is supposed to be sown with seeds, as of late November 2023 that has not happened. Friends has requested that a native seed mix be used in the hydroseeding.
The marsh at Piper Park is breeding habitat for the endangered Ridgway’s rail, so work cannot resume until September 1, 2024 when their breeding period ends. In the meantime, we expect that the site will have been evaluated. If a solution for disposal of the landfill of refuse can be agreed upon and the permits can be extended, then the marsh creation can resume in September 2024.
If the Piper Park site proves too challenging for the creation of new wetlands, then the City will have to locate another site. The Bon Air Bridge permits require that the compensation be implemented, even if the original plans prove unfeasible.